The information/communication industry is currently undergoing tremendous change from the constant evolution of new technologies and changing market conditions. In recent years, there has been a sharp increase in the demand for network bandwidth which has been driven by several trends, including the increasing number of networked computers exchanging data, the increasing need for networked computers to exchange ever-increasing quantities of data, and the increasing demands for data, video and voice over networked connections. In response to this demand, a variety of new computer network technologies have been developed that improve upon existing technologies by increasing the efficiency of data transmission, increasing the speed of data transmission, or both. One network technology incorporating both improvements is virtual circuit technology, such as is used in virtual circuit switched (VCS) networks such as frame relay (FR) or asynchronous transfer mode (ATM) networks.
The prevailing network topology of earlier generations of networks, such as Ethernet, Token Ring, and fiber distributed data interface, is one of a shared physical link. All of such networks"" endpoints are attached to the same network segment or link and share a single physical link having a fixed bandwidth. Such networks are generally referred to as broadcast networks because the data transmitted from a single station may be received by all other stations on that link. One disadvantage of broadcast networks is that the addition of more endpoints onto the link reduces the average bandwidth available to each station on that link.
As the demand for network bandwidth increased, new solutions were developed to overcome the shortcomings of shared bandwidth. One technology developed to improve network efficiency is commonly known in the art as switched networking or microsegmentation. Switched networks improve network bandwidth by establishing a dedicated link between an endpoint and a port on a network switch. The network switch generally routes all traffic in such a network by directing the traffic only to the stations that are the traffic""s destination. In doing so, no broadcasting occurs as in the shared link approach and the link""s full bandwidth is generally always available whenever the switch or endpoint seeks to transmit.
Additional improvements were made to switched networks to further improve bandwidth. VCS networks generally improve upon the switched network model by introducing virtual circuits and intelligent switching. Virtual circuit bandwidth allocation and transfer characteristics, such as delays and delay variations, can be tailored to the application traffic""s specific needs. Endpoints can request, through intelligence in the switches and signaling protocols, that the network provide the necessary bandwidth and quality of services needed on each virtual circuit. Primarily as a result of those improvements, VCS networks can simultaneously transport multiple types of network traffic, such as voice, data, and video, on a single physical link using different service types based upon the requirements of the traffic.
The improvements of virtual circuits permit increased bandwidth utilization in a Virtual Circuit Switched network. However this increased bandwidth utilization also increases the complexity of the VCS network. A single physical link can generally be subdivided into virtual paths (VP), which are further subdivided into virtual channels (VC). For example, typical ATM networks generally permit subdivision of a physical link into a maximum of approximately four thousand VPs, and the VPs may be further subdivided into a maximum of approximately sixty-four thousand VCs. Thus, there are potentially in excess of 256 million assignable virtual circuits within each dedicated link.
Prior to the widespread availability of signaling capability in VCS networks, all channel assignments were accomplished by the use of private (or permanent) virtual circuits (PVCs). PVCs are generally configured on a channel-by-channel basis by a manual assignment process occurring at both the switch console and endpoints. Typically, such PVCs are left unchanged, i.e., permanently setup for a specific entity, with a specific bandwidth and cost, until the channel is no longer needed. Because access is provided even when there is no traffic to send, or when less than full capacity is needed, PVCs can be costly and inefficient.
Additional VCS network technology improvements generally permit endpoints to transmit a signal request to the appropriate network device to request that a virtual circuit be set-up, connected, or released as needed. Such virtual circuits are known as switched virtual circuits (SVCs). In a network supporting SVCs, the virtual circuit setup and release requests are generally transmitted in a signaling channel. SVCs generally enable the dynamic utilization of bandwidth customized to each specific request from a network endpoint.
Although virtual circuit switched networks using SVCs can achieve increased network efficiency, they have generally been used primarily by telecommunications companies in large data hauling pipelines, with minimal direct effect on end users. In other words, end users are generally allowed only to request and pay for PVCs instead of more efficient SVCs. SVCs generally are not in more widespread use, from an end user point of view, because there apparently does not exist an infrastructure capable of properly managing dynamic SVC connections at the appropriate level in a VCS network. Generally, networks must be properly managed to ensure that adequate network performance is achieved and that end-user services are supported. However, the management of a VCS network is made difficult by, for example, the large number of potentially active virtual circuits, the ability for switched virtual circuits to be created and disconnected upon request, and the varying characteristics of each SVC, (such as bandwidth, duration and cost.
Management functions for the monitoring, operation and maintenance of a VCS network may include, for example, performance management (e.g., continuous in-service performance monitoring for pro-active warning of performance degradation), fault management (e.g., detection and location of network trouble and failure), and configuration management (provisioning). Some methods exist for analyzing a virtual connection in a telecommunications network. For example, a method of tracing the route of a virtual connection between two nodes through a telecommunications network is described in U.S. Pat. No. 5,675,578 to Gruber, et al., which patent is incorporated herein by reference. However, there exists a need in the prior art for a method and system to intelligently and dynamically manage switched virtual circuits in a VCS network so that end users can take advantage of the benefits and capabilities of switched virtual circuits.
Accordingly, it is an object of the present invention generally to integrate a network management system (NMS) with an VCS network to provide real-time switched virtual circuit management.
These and other objects, features and technical advantages generally are achieved by a system and method which manage switched virtual circuits for a virtual circuit switched network. A preferred embodiment method for managing switched virtual circuits in accordance with the present invention comprises determining that a switched virtual circuit has been established in a virtual circuit switched network by a network access device, monitoring the switched virtual circuit while the switched virtual circuit is active, and storing bandwidth and duration information for the switched virtual circuit upon termination of the switched virtual circuit. The method may further comprise reporting the bandwidth and duration information to the network access device after termination of the switched virtual circuit.
Another preferred embodiment method for managing switched virtual circuits in accordance with the present invention comprises receiving a request for establishing the switched virtual circuit from a network access device, generating connection parameters for establishing the switched virtual circuit in the virtual circuit switched network, and sending a reply including the connection parameters to the network access device. The generation of the connection parameters may comprise rules-based decision making using rules and objects representing characteristics of the virtual circuit network stored in a network administrator relational database. The reply may comprise provisioning information on establishing the switched virtual circuit in the virtual circuit switched network.
A preferred embodiment network management system in accordance with the present invention comprises a network access device gateway having an interface to a network access device in the virtual circuit switched network, a network administrator database connected to the gateway, the database including rules and objects representing characteristics of the virtual circuit switched network, and a rule engine connected to the gateway and having access to the rules and objects in the database. The rule engine is capable of generating switched virtual circuit connection parameters reply based upon the rules and objects, in response to a switched virtual circuit provisioning request received from the network access device via the gateway.
A preferred embodiment computer program product for managing a switched virtual circuit in a virtual circuit switched network in accordance with the present invention comprises a computer readable medium and a computer program stored on the computer-readable storage medium. The computer program comprises means for receiving a request for establishing the switched virtual circuit from a network access device, means for generating connection parameters for establishing the switched virtual circuit in the virtual circuit switched network, and means for sending a reply including the connection parameters to the network access device.
An advantage of the present invention is that it generally integrates a network management system (NMS) with an SVC network to provide real-time switched virtual circuit management, thus enabling end users to request and use switched virtual circuits and realize the benefits in cost and efficiency over private virtual circuits, and providing service providers (SPs) with increased bandwidth utilization and improved profitability.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.